Its still trial and error via blood tests.
You need to start NDT on the low side and will be hypothyroid for a few weeks.
If you start at full suggested dose, temporary hyPERthyroid is most certain to happen, avoid that at all possibilities. Been there, not good.
You increase NDT every 2 weeks to target point then retest.
Your NDT of choice should have a comparison chart on their website, Armour did years ago.
thanks, I am trying to switch to NDT by myself, w/o doctor's help,
You need tests as a guide though. Are you not in the US? NDT is Rx in US.
Only one I know that you can get online without RX is from Thiland. A NDT called "S" something.